class_docstr: Returns an iterator for ``mx.gluon.data.Dataloader`` so gluon dataloader
  can be used in symbolic module.
  
  Parameters
  ----------
  loader : mxnet.gluon.data.Dataloader
      Gluon dataloader instance
  data_name : str, optional
      The data name.
  label_name : str, optional
      The label name.
  dtype : str, optional
      The dtype specifier, can be float32 or float16
  
  Examples
  --------
  >>> import mxnet as mx
  >>> from mxnet.gluon.data.vision import MNIST
  >>> from mxnet.gluon.data import DataLoader
  >>> train_dataset = MNIST(train=True)
  >>> train_data = mx.gluon.data.DataLoader(train_dataset, 32, shuffle=True, num_workers=4)
  >>> dataiter = mx.io.DataloaderIter(train_data)
  >>> for batch in dataiter:
  ...     batch.data[0].shape
  ...
  (32L, 28L, 28L, 1L)
code: def getindex(self):
      return None
  
file_path: mxnet/python/mxnet/contrib/io.py
imports: from ..io import DataIter, DataDesc
  from ..None import ndarray
label_desc: Use image node_id 7 for calling the DataLoaderIter obj's underlying member method code with example usage: obj.getindex() and returns: None